Error 0x803100B3

Value: -2144272205 | 0x803100B3 | 2150695091

What does it mean ?

FVE_E_NOT_ALLOWED_TO_UPGRADE_WHILE_CONVERTING  
BitLocker cannot be upgraded during disk encryption or decryption.
Value: 179 | 0x00B3 | 0b0000000010110011

Where does it come from ?

FACILITY_FVE  
Full volume encryption
Value: 49 | 0x031 | 0b00110001

Other Errors for FACILITY_FVE